I. Field of the Invention
This invention relates to water heater constructions and a method of water heater fabrication and more particularly, to a novel method of insulating the exterior of the water heater tank.
II. Description of the Prior Art
It has been the general practice to insulate water heaters with fiberglass insulation material. The use of a rigid polyurethane foam insulation material, as in the present invention, provides several important advantages.
The conductivity factor of polyurethene foam is lower than that of fiberglass providing superior insulation properties. Thus, by the use of polyurethene foam, a given stand-by heat loss can be obtained with a substantially reduced insulation wall thickness as compared to that of conventional fiberglass insulation material. The result is a water heater of reduced diameter providing material savings in packaging and shipping costs. Also the rigidity of the form insulation as compared to that of fiberglass provides improved resistance of dents. This factor permits the use of less sophisticated shipping containers to further reduce the cost of packaging and shipping.